0.2.0 major revision

I realize it's a big PR, I'm not sure how much it was being used before but I've been using it in anger. I've added Test Kitchen coverage but I'm not using the DNS features much, mostly just DHCP and TFTP which is where my testing is at. 

Major features:
* duplicate options support for dhcp and dns conf files, driven by dhcp_options and dns_options attributes
* TFTP support
* Test Kitchen 1.0 coverage for Red Hat 5.9, 6.4, Debian 7.1 and Ubuntu 10.04, 12.04 and 13.04